Motor vehicles having bumper counter rotation brackets

ABSTRACT

A motor vehicle includes a first side member having first lower and upper darts. The motor vehicle also includes a second side member parallel with and spaced apart from the first side member, the second side member having second lower and upper darts. The upper darts are positioned between the lower darts and end portions of the respective first or second side members. The motor vehicle further includes first and second bumper brackets coupled to the end portion of the respective first or second side members, a bumper reinforcement member coupled to the first and second bumper brackets, and a counter rotation bracket coupled to the bumper reinforcement member and extending upwards from the bumper reinforcement member. The lower darts and the upper darts form a preferential buckling zone of the first and the second side members.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/296,701 filed Nov. 15, 2011.

TECHNICAL FIELD

The present disclosure is generally directed to motor vehicles havingbumper counter rotation brackets, and is specifically directed to bumpercounter rotation brackets that apply moment loads to the structure ofthe motor vehicles.

BACKGROUND

Motor vehicles are required to maintain structural integrity of vehiclesubsystems in the event of a collision with another vehicle orstationary object. In order to dissipate energy associated with acollision, vehicles include bumpers that absorb energy by resistingimpact and/or deforming to prevent a colliding vehicle from damaging thevehicle subsystems.

As the speed at which a collision takes places increases, the energyrequired to be dissipated by the bumper of the vehicle increases. Therequirement to dissipate increased energy may be complicated by unevenbumper heights of the colliding vehicles. Because the bumpers of thecolliding vehicles do not contact one another evenly, the energydissipation systems of the vehicles may not activate in the event of acollision, which may lead to damage to vehicle subsystems.

Accordingly, alternative systems and methods for dissipating the energyof a vehicle collision are needed.

SUMMARY

In one embodiment, a motor vehicle includes a first side member having afirst lower dart and a first upper dart, where the first upper dart ispositioned between the first lower dart and an end portion of the firstside member. The motor vehicle also includes a second side memberparallel with and spaced apart from the first side member, the secondside member having a second lower dart and a second upper dart, wherethe second upper dart is positioned between the second lower dart and anend portion of the second side member. The motor vehicle furtherincludes a first bumper bracket coupled to the end portion of the firstside member, a second bumper bracket coupled to the end portion of thesecond side member, a bumper reinforcement member coupled to the firstand second bumper brackets, and a counter rotation bracket coupled tothe bumper reinforcement member and extending upwards from the bumperreinforcement member. The lower darts and the upper darts form apreferential buckling zone of the first and the second side members.

In another embodiment, an impact energy dissipation system for a vehiclestructure including a first bumper bracket and a second bumper bracketcoupling the system to the vehicle structure, a bumper reinforcementmember coupled to the first and second bumper brackets and having abumper height, and a counter rotation bracket coupled to and extendingupwards from the bumper reinforcement member, where the counter rotationbracket has a bracket height that is at least approximately 50% of thebumper height.

In yet another embodiment, a motor vehicle includes a first side memberhaving a first lower dart and a first upper dart, where the first upperdart is positioned rearward of the first lower dart. The motor vehiclealso includes a second side member parallel with and spaced apart fromthe first side member, the second side member having a second lower dartand a second upper dart, where the second upper dart is positionedrearward of the second lower dart. The motor vehicle further includes afirst bumper bracket coupled to the end portion of the first sidemember, a second bumper bracket coupled to the end portion of the secondside member, a first gusset coupled to the first side member and thefirst bumper bracket, and a second gusset coupled to the second sidemember and the second bumper bracket. The motor vehicle also includes abumper reinforcement member coupled to the first and second bumperbrackets, and a counter rotation bracket coupled to the bumperreinforcement member and extending upwards from the bumper reinforcementmember, where the lower darts and the upper darts form a preferentialbuckling zone of the first and the second side members.

These and additional features provided by the embodiments describedherein will be more fully understood in view of the following detaileddescription, in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments set forth in the drawings are illustrative and exemplaryin nature and not intended to limit the subject matter defined by theclaims. The following detailed description of the illustrativeembodiments can be understood when read in conjunction with thefollowing drawings, where like structure is indicated with likereference numerals and in which:

FIG. 1 depicts a perspective view of an impact energy dissipation systemfor a motor vehicle including a counter rotation bracket according toone or more embodiments shown and described herein;

FIG. 2 depicts a side view of a portion of the impact energy dissipationsystem for a motor vehicle of FIG. 1 along line 2-2;

FIG. 3 depicts a side view of a motor vehicle including a counterrotation bracket in an undeformed state according to one or moreembodiments shown and described herein; and

FIG. 4 depicts a side view of a motor vehicle including a counterrotation bracket in a deformed state according to one or moreembodiments shown and described herein.

DETAILED DESCRIPTION

Referring to FIG. 1, an impact energy dissipation system for a vehiclestructure is schematically depicted. The impact energy dissipationsystem generally includes first and second side members, first andsecond bumper brackets, a bumper reinforcement member, and a counterrotation bracket. The first and second side members each include a lowerdart and an upper dart, where the upper darts are positioned between thelower darts and the end portions of the side members. The lower dartsand the upper darts form a preferential buckling zone of the first andthe second side members. The impact energy dissipation system furtherincludes first and second bumper brackets coupled to the end portions ofthe respective side members, a bumper reinforcement member coupled tothe bumper brackets, and a counter rotation bracket coupled to thebumper reinforcement member and extending upwards from the bumperreinforcement member. In the event of a collision with an incomingvehicle, the counter rotation bracket and the bumper reinforcementmember contact the incoming vehicle, and may apply a moment load thattends to buckle the side members at the preferential buckling zone. Theimpact energy dissipation system and vehicles incorporating the samewill be described in more detail herein with specific reference to theappended drawings.

Referring to FIG. 1, one embodiment of a motor vehicle 90 including animpact energy dissipation system 100 is schematically depicted. Thevehicle structure 92 of the motor vehicle 90 includes a first sidemember 110 that includes a first lower dart 112 and a first upper dart114, where the first upper dart 114 is positioned between the firstlower dart 112 and an end portion 116 of the first side member 110.Similarly, vehicle structure 92 of the motor vehicle 90 includes asecond side member 120 that includes a second lower dart 122 and asecond upper dart 124, where the second upper dart 124 is positionedbetween the second lower dart 122 and an end portion 126 of the secondside member 120. The impact energy dissipation system 100 of the motorvehicle 90 includes a first bumper bracket 130 coupled to the first sidemember 110 and a second bumper bracket 140 coupled to the second sidemember 120. The impact energy dissipation system 100 further includes abumper reinforcement member 150 coupled to the first and second bumperbrackets 130, 140, and a counter rotation bracket 160 coupled to thebumper reinforcement member 150 and extending upwards from the bumperreinforcement member 150.

The first and second lower darts 112, 122 and the first and second upperdarts 114, 124 form a preferential buckling zone 106 of the first andsecond side members 110, 120. The lower darts 112, 122 and the upperdarts 114, 124 arc local regions of the respective first and second sidemembers 110, 120 that decrease the buckling strength of the first andsecond side members 110, 120. As used herein, “buckling strength” refersto the maximum compressive strength an element can withstand beforefailing, where the compressive stress at the location of the failure isless than the compressive stresses the material of the element iscapable of withstanding. The buckling strength of an element can bedetermined experimentally or approximated using analysis, for example,finite element analysis. The darts 112, 122, 114, 124 may take a varietyof shapes, including having a chevron-like shape as illustrated in FIGS.3 and 4. The darts 112, 122, 114, 124 can be locally deformed regions ofthe first and second side members 110, 120 that interrupt the otherwisecontinuous first and second side members 110, 120. The darts 112, 122,114, 124 reduce the buckling strength of the first and second sidemembers 110, 120 such that, when the first and second side members 110,120 are subject to an impact force directed along the length of the sidemember 110, 120, the first and second side members 110, 120 tend to“close” the darts 112, 122, 114, 124, encouraging controlled deformationof the first and second side members 110, 120.

As illustrated in FIG. 1, in some embodiments, the impact energydissipation system 100 of the motor vehicle 90 further includes a firstgusset 132 coupled to the first side member 110 and the first bumperbracket 130, and a second gusset 142 coupled to the second side member120 and the second bumper bracket 140. The first and second gussets 132,142 may be located on the top surface 111, 121 of the respective firstside member 110 and the second side member 120. The first and secondgussets 132, 142 are located between the upper darts 114, 124 and theend portions 116, 126 of the first and second side members 110, 120. Thefirst and second gussets 132, 142 provide reinforcement between therespective side member 110, 120 and the bumper bracket 130, 140. Thefirst and second gussets 132, 142 are adapted to absorb force and momentapplied to the bumper brackets 130, 140 and direct any such force andmoment into the respective side member 110, 120. Additionally, the firstand second gussets 132, 142 may terminate before the first and secondupper darts 114, 124 of the first and second side members 110, 120 andconcentrate any moment into the side members 110, 120 in regions localto the upper darts 114, 124.

As discussed herein, the bumper reinforcement member 150 and the counterrotation bracket 160 may be located towards a front of the motor vehicle90, such that the bumper reinforcement member 150 forms a front vehiclebumper; or the bumper reinforcement member 150 and the counter rotationbracket 160 may be located towards a rear of the motor vehicle 90, suchthat the bumper reinforcement member 150 forms a rear vehicle bumper.Discussion of the motor vehicle 90 below is made in reference to thebumper reinforcement member 150 and the counter rotation bracket 160located towards a rear of the motor vehicle 90. As depicted in FIG. 1, aforward-facing surface 133 of the first bumper bracket 130 is orientedto face towards the first side member 110 and the first gusset 132. Aforward-facing surface 143 of the second bumper bracket 140 is orientedto face towards the second side member 120 and the second gusset 142.

Referring now to FIG. 2, the counter rotation bracket 160 and the bumperreinforcement member 150 are illustrated in cross-section. The counterrotation bracket 160 extends upwards from the bumper reinforcementmember 150. The counter rotation bracket 160 includes a contact portion162 and a reinforcement portion 164. The contact portion 162 isapproximately parallel with a face of the bumper reinforcement member150, shown here approximately parallel to the rearward-facing surface152. As depicted in FIG. 2, the reinforcement portion 164 is transverseto the contact portion 152. The contact portion 162 of the counterrotation bracket 160 is coupled to the bumper reinforcement member 150at a contact flange 163, while the reinforcement portion 164 of thecounter rotation bracket 160 is coupled to the bumper reinforcementmember 150 at a support flange 165. As depicted in FIG. 2, the contactflange 163 may define a lip 168 that is generally parallel to and offsetrearwardly from the contact portion 162 of the counter rotation bracket160. The lip may be positioned along the bumper reinforcement member 150such that the contact flange 163 of the counter rotation bracket 160overlaps both a portion of a top surface 158 of the bumper reinforcementmember 150 and a portion of a rearward surface 159 of the bumperreinforcement member 150. The support flange 165 of the counter rotationbracket 165 may be transverse to the reinforcement portion 164 of thecounter rotation bracket 160. The support flange 165 may be coupled tothe top surface 158 of the bumper reinforcement member 150. A variety ofattachment methods are contemplated including, but not limited to,structural spot welding, welding, riveting, bolting, or adhesivelybonding along the contact flange 163 and/or the support flange 165.

Referring to FIGS. 1 and 2, the counter rotation bracket 160 is sizedand positioned to provide increased protection to the motor vehicle 90while allowing the counter rotation bracket 160 to be packaged withinthe bodywork of the motor vehicle 90, including the bumper cover (notshown). The counter rotation bracket 160 extends a bracket width 167that is at least approximately ⅓ of a distance 104 between the firstside member 110 and the second side member 120. The counter rotationbracket 160 also has a bracket height 166 that is at least approximately50% of a bumper height 156 of the bumper reinforcement member 150.Further, the first bumper bracket 130 has a first bumper bracket height136 and the second bumper bracket 140 has a second bumper bracket height146. The first side member 110 has a first side member height 117 andthe second side member 120 has a second side member height 127 asevaluated in a vertical direction 80. As depicted in FIGS. 1 and 3, thefirst bumper bracket height 136 may be greater than the first sidemember height 117 and the second bumper bracket height 146 may begreater than the second side member height 127. The first gusset 132 mayhave a first gusset height 137 and the second gusset 142 may have asecond gusset height 147. As further depicted in FIGS. 1 and 3, thefirst bumper bracket height 136 may be greater than the first gussetheight 137 and the second bumper bracket height 146 may be greater thanthe second gusset height 147.

Components of the motor vehicle 90 may be made from a variety ofmaterials having appropriate material properties, including strength,modulus, impact resistance, and fracture toughness, for the application.The first and second side members 110, 120 may be made of a galvanizedsteel, for example, SCGA 570D. In one embodiment, the first and secondside members 110, 120 may include a “top hat” design, where each of thefirst and second side members 110, 120 are a weldment formed by aninside and an outside portion of the first and second side members 110,120. The first and second bumper brackets 130, 140 may be made of agalvanized steel, for example SCGA 270D, and may be deep-drawn fromsheet stock to the required shape. The bumper reinforcement member 150may be made of an aluminum alloy and may be formed using an extrusionprocess. The counter rotation bracket 160 may be made of an aluminumalloy or a corrosion resistant steel and may be formed using anextrusion process. The first and second gussets 132, 142 may be made ofa corrosion resistant steel, for example 440 stainless, and may be drawnfrom sheet stock to the required shape.

Referring now to FIGS. 3 and 4, a motor vehicle 90 including a counterrotation bracket 160 is illustrated before and after a collision with abarrier 200. A first, undeformed orientation of the motor vehicle 90 isillustrated in FIG. 3, while a second, deformed orientation of the motorvehicle 90 is illustrated in FIG. 4. The counter rotation bracket 160 ofthe motor vehicle 90 depicted in FIGS. 3 and 4 is located towards a rearof the motor vehicle 90, and the collision with the barrier 200represents a rear collision with the motor vehicle 90. Sensitivesubsystems of the motor vehicle 90, for example, a vehicle fuelingsystem 170, which includes a fuel filler inlet 172, a fuel filler neck174, and a fuel tank (not shown), are located forward of the bumperreinforcement member 150, and forward of the second lower and upperdarts 122, 124, such that the components of the vehicle fueling system170 are located forward of the preferential buckling zone 106. Whilediscussion of FIGS. 3 and 4 is made in reference to the second sidemember 120, the second lower and upper darts 122, 124, and the secondbumper bracket 140, it should be understood that during a collision,similar phenomena occur with regard to the first side member 110, thefirst lower and upper darts 112, 114, and the first bumper bracket 130.

Referring to FIG. 4, as the motor vehicle 90 impacts the barrier 200,the bumper portion 204 of the barrier first contacts the bumperreinforcement member 150. This impact initially causes the bumperreinforcement member 150 to translate towards the end portion 126 of thesecond side member 120 by deforming the second bumper bracket 140. Theimpact causes the second bumper bracket 140 to buckle, which causes thebumper reinforcement member 150 and the counter rotation bracket 160 topivot about the second bumper bracket 140 such that the counter rotationbracket 160 pitches towards the fascia portion 202 of the barrier 200.As the bumper reinforcement member 150 contacts the bumper portion 204of the barrier 200 and the counter rotation bracket 160 contacts thefascia portion 202 of the barrier 200, the continued application offorce due to the impact of the barrier 200 with the motor vehicle 90causes a counter-moment to be applied through the counter rotationbracket 160 into the second side member 120. The counter-moment isapplied to the second side member 120 in a direction that tends to“close” the second upper dart 124. Additionally, because the secondgusset 142 is attached to the second side member 120 and is locatedbetween the second upper dart 124 and the end portion 126, the secondgusset 142 tends to direct the counter-moment into a region of thesecond side member 120 immediately surrounding the second upper dart124.

With the bumper reinforcement member 150 contacting the bumper portion204 of the barrier 200, the counter rotation bracket 160 contacting thefascia portion 202 of the barrier 200, and the second side member 120 atleast partially deformed about the second upper dart 124, the continuedapplication of force due to the impact of the barrier 200 with the motorvehicle 90 causes a moment to be applied to the second side member 120in a direction that tends to “close” the second lower dart 122.

The second bumper bracket 140 has a bumper bracket buckling strength,and the second side member 120 has a side member buckling strength whichis evaluated at the second upper dart 124. In the embodiment of themotor vehicle 90 depicted in FIGS. 3 and 4, the second bumper bracket140 and the second side member 120 are designed such that the bumperbracket buckling strength is less than the side member bucklingstrength. Because the bumper bracket buckling strength is less than theside member buckling strength, the second bumper bracket 140 will reacha critical buckling load at a lower force than the second side member120 will reach a critical buckling load. Because the second bumperbracket 140 reaches its critical buckling load first, the second bumperbracket 140 will buckle and deform before the second side member 120,which allows the bumper reinforcement member 150 and the counterrotation bracket 160 to pitch forward to contact the barrier 200.Therefore, by buckling the second bumper bracket 140 before the secondside member 120, the counter rotation bracket 160 will be positioned toapply a counter-moment to the second side member 120.

Parameters of the barrier 200 and an impact between the motor vehicle 90and the barrier 200 are found in Federal Motor Vehicle Safety Standard(FMVSS) No. 301. FMVSS No. 301 requires a motor vehicle 90 to maintainintegrity of the vehicle fueling system 170 after the motor vehicle 90sustains an impact with a barrier 200 moving in excess of 80 kilometersper hour.

Without being bound by theory, as the bracket height 166 of the counterrotation bracket 160 increases, the greater the counter-moment that canbe applied through the first and second bumper brackets to the first andsecond side members 110, 120. Therefore, the bracket height 166 of thecounter rotation bracket 160 may be made as large as possible toincrease the counter moment, while maintaining the ability to packagethe counter rotation bracket 160 within the confines of the bodywork ofthe motor vehicle 90. Similarly, as the bracket width 167 of the counterrotation bracket 160 increases, the counter rotation bracket 160provides an increased zone of protection to motor vehicle 90 and itssubsystems. Bracket width 167 may be limited by the ability to packagethe counter rotation bracket 160 within the confines of the bodywork ofthe motor vehicle 90.

It should now be understood that the buckling of the first and secondside members 110, 120 and the first and second bumper brackets 130, 140dissipates energy associated with the barrier 200 impacting the motorvehicle 90. The preferential buckling zone 106 formed by the lower darts112, 122 and the upper darts 114, 124 allows the first and second sidemembers 110, 120 to buckle at a location rearward of the vehicle fuelingsystem 170. The buckling of the first and second side members 110, 120prevents energy due to the collision of the barrier 200 with the motorvehicle 90 from traveling forward beyond the preferential buckling zone106. By dissipating the energy caused by the collision rearward of thevehicle fueling system 170, damage to the vehicle fueling system 170 canbe minimized.

It is noted that the terms “substantially” and “about” may be utilizedherein to represent the inherent degree of uncertainty that may beattributed to any quantitative comparison, value, measurement, or otherrepresentation. These terms are also utilized herein to represent thedegree by which a quantitative representation may vary from a statedreference without resulting in a change in the basic function of thesubject matter at issue.

While particular embodiments have been illustrated and described herein,it should be understood that various other changes and modifications maybe made without departing from the spirit and scope of the claimedsubject matter. Moreover, although various aspects of the claimedsubject matter have been described herein, such aspects need not beutilized in combination. It is therefore intended that the appendedclaims cover all such changes and modifications that are within thescope of the claimed subject matter.

What is claimed is:
 1. A motor vehicle comprising: a first side membercomprising a first lower dart and a first upper dart, wherein the firstupper dart is positioned between the first lower dart and an end portionof the first side member; a second side member parallel with and spacedapart from the first side member, the second side member comprising asecond lower dart and a second upper dart, wherein the second upper dartis positioned between the second lower dart and an end portion of thesecond side member; a first bumper bracket coupled to the end portion ofthe first side member; a second bumper bracket coupled to the endportion of the second side member; a first gusset coupled to the firstside member and the first bumper bracket; a second gusset coupled to thesecond side member and the second bumper bracket; a bumper reinforcementmember coupled to the first and second bumper brackets; and a counterrotation bracket coupled to the bumper reinforcement member andextending upwards from the bumper reinforcement member, wherein: thefirst gusset is located between the first upper dart and the end portionof the first side member; the second gusset is located between thesecond upper dart and the end portion of the second side member; thelower darts and the upper darts form a preferential buckling zone of thefirst and the second side members, and a bumper bracket bucklingstrength of the first and second bumper brackets is less than a sidemember buckling strength of the respective first and second sidemembers.
 2. The motor vehicle of claim 1, wherein the bumperreinforcement member is located towards a rear of the motor vehicle. 3.The motor vehicle of claim 1, wherein the bumper reinforcement member islocated towards a front of the motor vehicle.
 4. The motor vehicle ofclaim 1, wherein the preferential buckling zone of the first and secondside members is rearward of a vehicle fueling system.
 5. The motorvehicle of claim 1, wherein: the counter rotation bracket comprises acontact portion and a reinforcement portion; the contact portion isparallel with a rearward-facing surface of the bumper reinforcementmember; and both the contact portion and the reinforcement portion arecoupled to the bumper reinforcement member.
 6. The motor vehicle ofclaim 1, wherein a bracket height of the counter rotation bracket is atleast approximately 50% of a bumper height of the bumper reinforcementmember.
 7. The motor vehicle of claim 1, wherein the counter rotationbracket extends a bracket width that is at least approximately ⅓rd of adistance between the first side member and the second side member. 8.The motor vehicle of claim 1, wherein the buckling strength of the firstside member and the second side member exhibit reduced buckling strengthat the first lower dart and the second lower dart, respectively, suchthat the end portions of the first side member and the second sidemember tend to deform downwards when impacted.
 9. The motor vehicle ofclaim 2, wherein: the first gusset is located on the top surface of thefirst side member; the second gusset is located on the top surface ofthe second side member; and the forward-facing surface of the firstbumper bracket is oriented to face towards the first side member andfirst gusset and the forward-facing surface of the second bumper bracketis oriented to face towards the second side member and the secondgusset.
 10. The motor vehicle of claim 9, wherein a first bumper bracketheight of the first bumper bracket and a second bumper bracket height ofthe second bumper bracket evaluated in a vertical direction is greaterthan a first side member height of the first side member and a secondside member height of the second side member, respectively.
 11. Themotor vehicle of claim 9, wherein a first bumper bracket height of thefirst bumper bracket and a second bumper bracket height of the secondbumper bracket evaluated in a vertical direction is greater than a firstgusset height of the first gusset and a second gusset height of thesecond gusset, respectively.
 12. The motor vehicle of claim 9, whereinthe first gusset and the second gusset terminate at a position rearwardof the first upper dart and the second upper dart, respectively.
 13. Themotor vehicle of claim 5, wherein the reinforcement portion of thecounter rotation bracket is transverse to the contact portion of thecounter rotation bracket.
 14. The motor vehicle of claim 5, wherein: thecounter rotation bracket further comprises a support flange; and thesupport flange is coupled to the reinforcement portion, transverse tothe reinforcement portion, and coupled to a top surface of the bumperreinforcement member.
 15. The motor vehicle of claim 5, wherein: thebumper reinforcement member is located towards a rear of the motorvehicle; the counter rotation bracket further comprises a contactflange; and the contact flange is coupled to the contact portion andoverlaps a portion of top surface of the bumper reinforcement member anda portion of the rearward surface of the bumper reinforcement member.16. The motor vehicle of claim 15, wherein the contact flange comprisesa lip that is generally parallel to and offset rearwardly from thecontact portion of the counter rotation bracket.
 17. A motor vehiclecomprising: a first side member comprising a first lower dart and afirst upper dart, wherein the first upper dart is positioned between thefirst lower dart and an end portion of the first side member; a secondside member parallel with and spaced apart from the first side member,the second side member comprising a second lower dart and a second upperdart, wherein the second upper dart is positioned between the secondlower dart and an end portion of the second side member; a first bumperbracket coupled to the end portion of the first side member; a secondbumper bracket coupled to the end portion of the second side member; abumper reinforcement member coupled to the first and second bumperbrackets; and a counter rotation bracket coupled to the bumperreinforcement member and extending upwards from the bumper reinforcementmember, wherein: the lower darts and the upper darts form a preferentialbuckling zone of the first and the second side members; a bumper bracketbuckling strength of the first and second bumper brackets is less than aside member buckling strength of the respective first and second sidemembers; and the first and second side members exhibit reduced bucklingstrength at the first lower dart and the second lower dart,respectively, such that the end portions of the first and second sidemembers tend to deform downwards when impacted.
 18. The motor vehicle ofclaim 17, wherein the bumper reinforcement member is located towards arear of the motor vehicle.
 19. The motor vehicle of claim 17, furthercomprising: a first gusset coupled to the first side member and thefirst bumper bracket; and a second gusset coupled to the second sidemember and the second bumper bracket.
 20. The motor vehicle of claim 17,wherein: the counter rotation bracket comprises a contact portion and areinforcement portion; the contact portion is parallel with arearward-facing surface of the bumper reinforcement member; and both thecontact portion and the reinforcement portion are coupled to the bumperreinforcement member.